MvvmCross Xamarin IOS“找不到 ViewModel 的视图”

Question

我将 Storyboard 与 MvvmCross 和 Xamarin iOS 一起使用。 A 我遇到了异常。这是堆栈跟踪：

{System.Collections.Generic.KeyNotFoundException：找不到 Kosht​​.Core.ViewModels.TutorialViewModel 的视图 在 MvvmCross.Views.MvxViewsContainer.GetViewType (System.Type viewModelType) [0x00081] in :0 在 MvvmCross.Presenters.MvxAttributeViewPresenter.GetPresentationAttribute (MvvmCross.ViewModels.MvxViewModelRequest 请求) [0x0000c] in :0 在 MvvmCross.Presenters.MvxAttributeViewPresenter.Show (MvvmCross.ViewModels.MvxViewModelRequest 请求) [0x00000] in :0 在 MvvmCross.Platforms.Ios.Views.MvxIosViewDispatcher+c__DisplayClass2_0.b__0 () [0x0001d] in :0 在 MvvmCross.Base.MvxMainThreadAsyncDispatcher+c__DisplayClass0_0.b__0 () [0x00000] in :0 在 MvvmCross.Base.MvxMainThreadAsyncDispatcher+c__DisplayClass1_0+d.MoveNext () [0x00011] in :0 --- 从先前抛出异常的位置结束堆栈跟踪 --- 在 System.Runtime.CompilerServices.AsyncMethodBuilderCore+c.b__6_0（System.Object 状态）[0x00000] 在 /Library/Frameworks/Xamarin.iOS.framework/Versions/11.14.0.14/src/Xamarin.iOS/mcs/class/参考源/mscorlib/system/runtime/compilerservices/AsyncMethodBuilder.cs:1018 在 Foundation.NSAsyncSynchronizationContextDispatcher.Apply () [0x00000] 在 /Library/Frameworks/Xamarin.iOS.framework/Versions/11.14.0.14/src/Xamarin.iOS/Foundation/NSAction.cs:178 --- 从先前抛出异常的位置结束堆栈跟踪 --- 在（包装器托管到本机）UIKit.UIApplication.UIApplicationMain(int,string[],intptr,intptr) 在 /Library/Frameworks/Xamarin.iOS.framework/Versions/11.14.0.14/src/Xamarin.iOS 中的 UIKit.UIApplication.Main（System.String[] args，System.IntPtr 主体，System.IntPtr 委托）[0x00005] /UIKit/UIApplication.cs:79 在 /Library/Frameworks/Xamarin.iOS.framework/Versions/11.14.0.14/src/Xamarin.iOS 中的 UIKit.UIApplication.Main (System.String [] args, System.String principalClassName, System.String delegateClassName) [0x0002c] /UIKit/UIApplication.cs:63 在 Kosht​​.iOS.Application.Main (System.String[] args) [0x00001] 在 /Users/vadimkhadyka/Projects/Kosht​​/src/Mobile/Kosht​​.iOS/Main.cs:13 }

我的教程视图：

[MvxViewFor(typeof(TutorialViewModel))]
    [MvxFromStoryboard("Tutorial")]
    [MvxRootPresentation]
    public partial class TutorialView : BaseViewController<TutorialViewModel>
    {
        public TutorialView() : base("TutorialView", null)
        {
        }

        public override void ViewDidLoad()
        {
            base.NavigationController.NavigationBarHidden = true;
            base.ViewDidLoad();
        }
    }

我的 BaseViewController：

    public class BaseViewController<TViewModel> : MvxViewController,  IBaseView<TViewModel> where TViewModel : BaseViewModel
        {
            protected BaseViewController(string nibName, NSBundle bundle) : base(nibName, bundle)
            {
            }

            public BaseViewController(IntPtr handle) : base(handle)
            {
            }

            public BaseViewController()
            {
            }

            public override void ViewDidLoad()
            {
                base.ViewDidLoad();
                // Perform any additional setup after loading the view, typically from a nib.
            }

            public new TViewModel ViewModel => (TViewModel)base.ViewModel;


            public override void DidReceiveMemoryWarning()
            {
                base.DidReceiveMemoryWarning();
                // Release any cached data, images, etc that aren't in use.
            }
}

如果我删除BaseViewController 并从MvxViewController 继承我的TutorialView，一切正常，但对于我的基类，我得到了例外。

Answer 1

改变这一行

public class BaseViewController<TViewModel> : MvxViewController,  IBaseView<TViewModel> where TViewModel : BaseViewModel

到

public class BaseViewController<TViewModel> : MvxViewController<TViewModel> where TViewModel : class, IMvxViewModel

并删除它

public new TViewModel ViewModel => (TViewModel)base.ViewModel;